How do you simplify this algebra problem?

8{[5(a-5)+19]-[3(3a-3)+4]}

I need to simplify it for solving by combining like terms. I put -32a-72 into the program I'm using, but it was flagged as wrong. I've been reworking similar problems all night to no avail. Please give me a STEP BY STEP EXPLANATION, including what I'm doing wrong.

As far as I know you're supposed to work inside the brackets out, like this:

1. 8{[5(a-5)+19]-[3(3a-3)+4]}

a) 8[5a-25+19] [-9 + 9-12]

b) 8[5a-6] [-9a-3]

c) [40a-48] [-72a -24]

d) My Answer -32a-72

It is wrong and I get two more tries to answer it before the program makes me rework a similar problem AGAIN (I've already done it at least 8 times) and I have four more problems like this to do. I'll be all night if I don't get this. HELP!!!

Comments

  • 8{[5(a-5)+19]-[3(3a-3)+4]}

    8( (5a - 25 + 19) - (9a -9 +4) )

    8( (5a - 6) - (9a - 5)

    8( 5a - 6 - 9a + 5

    8( -4a -1)

    = - 32a - 8

    In step 1 of your working you have multiplied the 4 by the three but its outside of the brackets, and you miltiplied by 8 before the last step, you should solve everything inside the brackets before you multiply by 8.

    Hope it makes sense, and I hope it helped :)

  • It get wrong in ur a) step. It suppose to be like this

    8{[5a-25+19] -[9a + 9-12]}

    I think u can do the rest by urself. Be careful though. U made a very small mistake.

    This is my answer -32a -8

  • from what I remember this is my best shot:

    Work out the inner parenthesis first each time.

    So i reduced the 5a group and the -9 group at the same time.

    I then removed the parenthesis from the -9 group, and REMEMBERED TO CHANGE EVERY SIGN BEACSUE THERE IS A NEGITIVE IN FRONT OF THE (.

    I then had 5a - 25 + 19 + 9a =5.

    I reduced to 112a - 1 which I think is the correct answer.

    I think you got confused with the - ( ), Good try anyway!

  • 8((5a-25+19)-(9a-9+4))

    8(5a-6-9a+5)

    8(-4a-4)

    -32a-8 is your final answer

    basically when you have negative outside of bracket in the first step of my answer

    you have to multiple negative one to every number inside the bracket, but you can simplfy what is inside the bracket first so -9+4 becomes -5 multiplied by -1 due to the negative sign outside the bracket, so you get +5 as so in the second line... then its just collecting liked terms and expanding or distribution...

    good luck

  • 14c^3-D^2 - 21c^2d^3 ----------------------------- 14cd^2 14c^3-D^2.....21c^2d^3 = ------------- - --------------- 14cd^2.........14cd^2 ............3cd = c^2 - ----- .............2 = c^2 - 3/2 cd do not recommendations about the dots. I had to characteristic them to save the numbers in positions.

  • You don't.

Sign In or Register to comment.